[HIVE-675] Add Database/Schema support to Hive QL

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.6.0
• Component/s: Metastore, Query Processor
• Hadoop Flags: Reviewed
• Release Note: This ticket adds the ability to CREATE DATABASE, DROP DATABASE, and USE <database>. Please note that Hive does not yet support the ability to run a query that selects from tables in more than one database.
• Assignee: Carl Steinbach
• Reporter: Prasad Chakka
• Created: 22/Jul/09 21:26
• Updated: 30/Jul/14 05:04
• Resolved: 16/Sep/10 17:09

Description

Currently all Hive tables reside in single namespace (default). Hive should support multiple namespaces (databases or schemas) such that users can create tables in their specific namespaces. These name spaces can have different warehouse directories (with a default naming scheme) and possibly different properties.

There is already some support for this in metastore but Hive query parser should have this feature as well.

Issue Links

• blocks: HIVE-1010 Implement INFORMATION_SCHEMA in Hive
• duplicates: HIVE-191 Update methods in Hive class to specify database name
• is blocked by: HIVE-850 moving SessionState from ql to common
• is blocked by: HIVE-584 Clean up global and ThreadLocal variables in Hive
• is depended upon by: HIVE-1591 Lock the database also as part of locking a table/partition
• is depended upon by: HIVE-1591 Lock the database also as part of locking a table/partition
• is duplicated by: HIVE-847 support show databases
• is related to: HIVE-1590 DDLTask.dropDatabase() needs to populate inputs/outputs
• is related to: HIVE-846 move hive tables from one database to another
• is related to: HIVE-847 support show databases
• is related to: HIVE-848 support mutilpe databse support in HWI
• is related to: HIVE-849 <database_name>.<table_name>.<column_name> not supported
• is related to: HIVE-1537 Allow users to specify LOCATION in CREATE DATABASE statement
• is related to: HIVE-850 moving SessionState from ql to common
• is related to: HIVE-1960 Database feature should be documented
• is required by: HIVE-1517 ability to select across a database
• relates to: HIVE-1607 Reinstate and deprecate IMetaStoreClient methods removed in HIVE-675
• relates to: HIVE-6601 alter database commands should support schema synonym keyword
• relates to: HIVE-1636 Implement "SHOW TABLES {FROM | IN} db_name"